Technical Abstract:
Thlaspi caerulescens is a zinc and cadmium hyperaccumulator, capable of storing up to 30,000 ppm Zn or 10,000 ppm Cd in the shoots without exhibiting toxicity symptoms. Previous research demonstrates the heavy metal hyperaccumulation seen in T. caerulescens is due to altered regulation of uptake, transport and sequestration processes relative to non-accumulating plant species. However a number of questions regarding the fundamental mechanisms of plant mineral transport remain. For example, is metal hyperaccumulation a cellular trait, or does it require primarily the functioning of more complex tissues and organs? By characterizing the physiological and molecular differences between these species at the cellular level, we can better understand the mechanisms underlying the hyperaccumulation phenotype. To that end, we have created suspension cell lines from the zinc/cadmium hyperaccumulator T. caerulescens and a related non-hyperaccumulator T. arvense. We are examining the cellular characteristics, both at the molecular and physiological levels, associated with Zn and Cd transport, accumulation and tolerance in these two cell lines, as well as in Arabidopsis thaliana suspension cells. In this presentation, we will describe the procedures for development of T. caerulescens and T. arvense suspension cell lines, as well as the physiological and molecular characterization of these suspension cell lines.